Gets from the device a sequence of characters of size n and store it in s. The State::Fail state flag is set if any issue happens during the reading operation. In case the number or characters read does not correspond to the number of characters to read n, the State::End state flag is also set.

Puts the sequence of characters s of size n to the device. The State::Error state flag is set if any issue happens during the wrting operation. In case you attempt to write on the device while it is open in read-only mode, the State::Fail state flag will be set.